Switch



P. S. BEAR Dec.- 28, 1937.

SWITCH Y 2 Sheets-She'et l Filed Dec. 26, 1934 l al nella P. S` BEAR Dec. 2s, 1937.

SWITCH Filed Deo. 26, 1934 2 Sheets-Sheet 2 im m M Patented Dec. Z8, 1.937

UNITED: STATES ?ATENT OFFICE SWITCH Paul S. Bear Application December 26, 1934, Serial No. 759,153

34 Claims.

'I'his inventionV relates to switches,` and is more particularly directed toswitches of the magnetic type employed for heavy duty purposes, such as for power line switching, and the like, although its use is not to be so limited, as it may be employed for any desired switching or relay purpose.

In its preferred form, the present switch comprises a pair of metallic cup electrodes, carried in spaced relationship by an insulating member, such as a molded ceramic spacer having an inwardly extending annular barrier portion separating the two electrodes, orA any similar type of spacing member. The switch is mounted in position with the two electrodes in vertical alignment, and a magnetically responsive plunger or amature is carriedA therebetween, being supported at its lower end in a body of mercury disposed in the lower electrode. The armature is guided for vertical reciprocatory Vmovement by the barrier portion of the ceramic spacer, and, upon attraction, displaces suicient mercury from the lower electrode to produce a mercury to mercury contact between the upper and lower electrodes, completing the circuit.

One object of the present invention is the provision of a heavy duty switch capable of remote control and having mercury to mercury making and breaking of contact between two metallic electrodes which, in themselves, form the switch housing.

Another object of the present invention is to provide a switch in which making and breaking of contact is accelerated and occurs over a sharply deiined edge of an insulating member, whereby positive and rapid action of the switch is assured. Also, repeat performance of the switch is likewise secured, since the switch makes and breaks contact at the same point during succeeding operations, whereby the point of contact may be clenitely ascertained.

'Ihe present switch construction preferably employs, in addition to the mercury within the electrodes, a liquid ller for facilitating heat equalization and heat dissipation which, at the same time, has the ability to maintain the metal with which it is in Contact clean and bright. Such liquids as triethanolamine or its equivalents, such as other of the ethanolamines or glycerin, may be employed, as disclosed in the copending application of Paul S. Bear and Herbert E. Bucklen, Serial No. 745,842, led September 28, 1934, and the broad concept of using such a lill in a mercury switch is not a part of the present invention.

The armature employed in the present invention is of a paramagnetic metal and is desired so that it cannot be displaced when once assembled in position within the switch housing. The armature is provided with a relatively small bearing surface so that its frictional resistance to movement, with respect to the barrier surface, is maintained at a minimum.

Another advantage of the present construction is the particular assembly employed, whereby the two cup-shaped electrodes are held in xed position and in sealed engagement with the ceramic spacer, so that the pressures produced by increase in heat within the switch, or by arcing, will not destroy or injure. the switch structure, as has been known to happen with sealed glass tube mercury switches. Thus, the switch can stand higher currents, and more rapid making and breaking of contact. The liquid fill also assists in dissipating heat equally to all parts of the switch structure, so that heat radiation from the switch structure is facilitated to maintain the operating temperature of the switch at a minimum.

A still further object of the present invention is to provide a switch of this type which requires no inleads, has no exposed moving parts, and operates with little or no noise.

In addition, the present switch structure is adapted for use in the control of heating, ventilating, and air conditioning equipment for railroad cars and the like, in which event it is preferably mounted in such manner as to be unaffected by shocks or vibrations incident to movement of the cars.

I have also provided a switch structure of this type in which the actuating means for the switch is selective in operation to control a plurality of circuits, either serially or separately. In this connection the switch may be employed for sign flashing equipment, three-wire temperature and limit control switches, and for other similar control purposes. In addition, the switch may be employed in situations wherein two separate circuits are to be controlled by two separate actuating means, the one switch structure thus serving a dual purpose.

The switch of the present invention is economical in manufacture, can be quickly and easily assembled, and possesses marked operating characteristics, such as repeat performance and relatively great durability.

Other objects and advantages of the present invention will appear more fully from the following detailed description, which, taken in connection with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of my invention.

In the drawings:

Figure 1 is a vertical sectional view through a preferred form of switch;

Figure 2 is a horizontal sectional view taken substantially on the line 2-2 of Figure l;

Figure 3 is a perspective view of the armature member shown in Figures 1 and 2;

Figure 4 is a vertical sectional view through a modified form of switch;

Figure 5 is a diagrammatic View showing one manner in which the switch o-f the present invention may be employed.

Figure 6 is a detailed perspective View of a modified form of ceramic spacer;

Figure 'l is a detailed perspective view of a modified armature;

Figure 8 illustrates one manner of mounting the switch in position to withstand shock and vibration;

Figure 9 is a sectional View through a modified switch structure;

Figure 10 is a. sectional view through the armature shown in Figure 9 and Figure 1l is a view, partly in section, of a dual purpose switch constructed in accordance with the teachings of the present invention.

Referring now in detail to the drawings, in Figure 1 I have shown a switch comprising a rst cup-shaped metallic electrode 6, a second cup-shaped metallic electrode "I, each of the electrodes having, about the defining ends thereof, threaded portions 8 adapted to be engaged in correspondingly threaded recesses formed in a ceramic spacing member 9. The electrodes 6 and 'I are threaded tightly into the spacer member 8, and are sealed with respect thereto by means of gaskets Ill, interposed between the ends of the electrodes and the inwardly extending portion I2 of the spacing member. This forms a substantially liquid and gas tight switch housing, the two electrodes being insulated from each other by the annular portion of the spacing member extending therebetween between the gaskets I0. Preferably the electrodes are provided with an exterior coating of cellulose acetate II, or an initial coating of bakelite covered with cellulose acetate, for shock-absorbing-purposes and to provide an external surface that can be colored or decorated in any desired manner.

The inwardly extending portion I2 of the member 9 is -provided with an annularly flanged beveled rim portion I3, as shown; which has an outwardly tapering surface adapted to define, with the inner Wall of the lower end of the electrode 6, an annular groove I4,, which groove ares inwardly toward the center of the switch housing along the annular surface I3.

The lower electrode I5 is preferably lled with mercury, which normally extends a substantial distance upwardly within the space defined by the inwardly extending portion I2 of the spacer. In addition, an annular ring of mercury I6 is normally disposed within the annular groove or space I4. Contact over the sharp defining surface of the member I3 is established between the mercury bodies upon raising of the level of the mercury I5 by reason of depression of the reciprocatory plunger or armature.

The switch housing is also filled partially with a liquid filler, such as triethanolamine, glycerin, or equivalent liquids, which have the capacity of of suppressing arcs and maintaining all metallic contacting surfaces clean and bright. A suitable expansion space I8 is provided above the liquid ll I'I, and the switch housing itself is sealed by means of the tapered screw I9 threading into one end of the electrode 6. The particular method of filling such a switch and sealing the same is described in detail in the copending application of myself and Herbert E. Bucklen, Serial No. 745,842, filed September 28, 1934.

Secured to the electrode 6 is a terminal lead 20, which may be welded or otherwise suitably secured to the exterior surface of the electrode 6, and which does not extend through into the interior of the switch housing. Similarly, a conductor 22 is secured to the exterior surface of electrode 1.

Referring now in detail to the movable armature or plunger for operating the switch member, reference is made to Figure, in which this member is shown in perspectivev detail. The plunger 23 .is of generally cruciform design, having the four bearing surfaces 24 adapted to have guiding engagement within the extending portion of the member 9. The plunger, at the lower end of the bearing surfaces 24, is provided with normally extending shoulders 25, which are adapted toengage under the lower surface of the extending Vportion I2 of the spacer 9, to prevent or limit upward movement of the plunger 23 with respect to the switch housing. This effectively prevents displacement of the plunger upwardly out vo1.' alignment with the opening. Below the abutment or stop surfaces 25 are extending dared leg portions 26, Awhich are for the purpose of 'pro'- -viding increased displacement area for the plunger. 'I'he legs 26-of the plunger arealso effective to limit the downward movement of the plunger within the switch housing, so that at no time will it be displaced below a point wherein the upper portion thereof is still disposed within the opening through which the plunger reciprocates.

The upper portion of the plunger, above the bearing surface 24, is cut away, to form vertically extending surfaces 21 upon each of the four extending legs of the plunger, so that the plunger, itself, adjacent the surface I3 where contact is made or broken, is spaced a sufiicient distance therefrom to avoid any possibility of arcing over from the mercury I6 to the plunger member 23, which would defeat the purposes of the switch.

The ceramic spacer 9 is surrounded by a magnetic coil indicated at 30, and having leads 32 connected to any suitable source of remotely controlled energizing power. Upon actuation of the coil 30, the plunger 23 is drawn downwardly within the opening, and its increased mass within the body of mercury I5 displaces this mercury upwardly through the internal opening in the spacer 9, the mercury rising upwardly and eventually flowing over the dening edge of the upper portion I3 of the spacer, whereupon it contacts the mercury I6 in the annular groove I4, and thus produces a mercury to mercury contact between the electrodes 6 and l, completing a circuit between conductors 20 and 22.

Due to the relatively large mass of the plunger 23 as it moves downwardly in the body of mercury I5, and the relatively small area through which the upper portion of the body of mercury I5 may move into contact with the mercury I6, the mercury within the annular opening in the member I2 rises at a high rate of speed upon actuation of the plunger 30, and thus positively provides for making of contact at an accelerated rate,'thus preventing sputtering or arcing at the contact about the annular rim I3. In the same manner, upon release of the energizing force in coil 30, the buoyancy of the plunger 23, with respect to the mercury I5, causes the plunger to pop upwardly, thus creating a rapid and accelerated breaking of the contact about the annular rim I3. As will be noted in Figure 2, the body of mercury I rising upwardly through the annular opening is such that substantially uniform contact is obtained about the entire peripheral edge of the rim I3, whereby the mercury makes contact over a relatively large surface, thus providing for relatively heavy duty operation, since suflicient mercury contact is provided to carry a relatively heavy current. This is desirable where the switch is employed for power line protection purposes or in similar situations.

In initially assembling the switch, the plunger 23 is first placed within the electrode 1, and the electrode is then threaded into the spacer 9. This secures the plunger in position within the annular opening within the portion I2 thereof. The second electrode 6 is threaded into the spacer, and mercury is poured into the switch through the opening occupied by the screw I9. A suflicient amount of mercury is introduced to dispose the bodies of mercury I5 and I6 in the relative positions shown in Figure l. The liquid fill is then introduced, the switch housing being evacuated of air or the like by a process disclosed inedetail in the above mentioned copending application, and which forms no part of the present invention.

Referring now in detail to Figure 4, the operating characteristics of the switch showntherein are similar to those described in connection with Figures 1 to 3, except that the switch shown in Figure 4 is capable of operating in alternate vertical positions. In this particular embodiment, the metallic cup-shaped electrodes '6' tand il are substantially identical, and areprovided, as previously described, with the conductors 20 and 22. The ceramic spacing member 9 of this particular embodiment has opposed threaded recesses forming receiving means for the ends of the cup-shaped electrodes 6' and 1', there being suitable gaskets interposed therebetween, and is provided with an inwardly extending portion oi generally T-shaped section, this portion being Vindicated at 35 in Figure 4, and having opposed annularly tapered rim surfaces .36 and 31, corresponding to the surface I3 of Figure l. The central portion of the member 9 ,is :cut away, defining an annular cylindrical opening 38, in which a two-piece plunger member 39 is adapted to have reciprocatory movement.V The plunger member 39 is provided with opposed outwardly flaring end portions Il and 42,'for'limiting its movement in opposite directions, whereby the plunger is at all times confined for movement within the opening 38,

In either position of the switch, the lowermost electrode is adapted to have a substantial quantity of mercury, indicated at 43, therein, which mercury extends up a suflicient distance within the annular opening 38 so that upon downward movement of the plunger 39 the mercury will run over the defining edge of the rim 36 at the the T-shaped section 35, and the plunger. The switch is provided with the energizing coil 30, corresponding to the coil 3G of Figure l, and having the lead 32 leading to a source of control.

Annular openings 46 are also formed in the extending legs of the plunger, so that when .the switch is reversed in position, with the cup-shaped electrode 1 in inverted position, and the cupshaped electrode E' disposed therebeneath, the opening 46 will prevent arcing over of the mercury in the'annular groove about the surface 31 and the lower end of the cup-shaped electrode 1' with the plunger. Outside of the reversibility of operation of this sadtch, it is formed and assembled in the same manner as described in connection with the switch shown in Figure 1.

In Figure 5 I have shown, somewhat' diagrammatically, one manner in which the switch of the present invention may be employed. In this particular embodiment of the invention, a switch corresponding to the switch of Figure l is shown, and the leads 32 from the coil 30 are extended to a suitable source of powerI supply, indicated by the transformer 56, there being a pair of spaced contacts 50 in the circuit which are normally open. These contacts are preferably surrounded :by'a magnetic member 52, and upon response of the thermally sensitive member 55 tc conditions within an enclosure or the like, the carrier 54 .is moved toward the magnet 52, and at the same time'carries the bridging member 53 into engagement with the contact 52 closing the circuit therebetween. Closure of these contacts results in energization'of coil 36, closing the connection between conductors 2G and 22, and thereby operating suitable oil burning apparatus, shown diagrammatically at 51. It is obvious, however, that any .other suitable control might be effected `by closing of the contact between conductors 26 and 22, without'in any way departing from the scope and 'spirit of the present invention.

nIn Figure 6 I have shown a modied form of ceramic spacing ring, adapted to engage the cup member electrode, such as the shell 6 shown in .Figure l. The spacing ring of this invention comprises a ceramic moulded member 66, which has an inner extending flange portion 62 extendlng 'within the vperipheral end of the shell 6. At its upper end. the member V62 has an outwardlybeveled surface 63 in which are formed a plurality-of pockets 64 having mercury 65 disposed therein. This mercury stays within the pockets when the armature 23 is in its uppermost position, in the same manner that the annular ring of mercury IB remains in contact with the inner surface of the shell 6 as shown in Figure 1.

Upon attraction of the plunger or armature by means of the coil, the mercury rises within the .annular opening formed internally of the flanged portion 62 of the ceramic ring, and iiows over the edge of the ring between the surfaces 62 and 63 into engagement with the mercury 465 in the pockets 64, thus effecting contact with the electrode 5.

By reason of these pockets, any excess mercury drains down into the reservoir portion of 'the lower electrode 1 of the switch structure, and only a predetermined quantity of'J mercury is retained Within the pockets 64. rI'liisprovides for a more even and more positive contact of the mercury between the cups 6 and 1, since it is not necessary that the switch be mounted in exlact vertical position. as is the case in connection withFigure 1, wherein a slight variation from the vertical will allow the mercury to provide for contact at only one point of the annular ring i6 oi mercury. With the modied structure shown in Figure 6, contact is effected at a plurality of pockets 64 regardless of the vertical positioning of the switch. By the provision of the annular series of mercury-retaining pockets, the bodies of mercury in the pockets are inherently stable, and when the switch is mounted in position on board a boat or train, any impacts due to movement will not tend to displace the individual bodies of mercury. As a consequence, mercuryto-mercury contact is maintained even with the switch mounted at an angle to the normal vertical operating position. The mercury does not run around the annular recess when the pockets are employed, and consequently does not dribble over the edge of the ceramic flange. 'I'he provision of the pockets retaining individual more or less inherently stable bodies of mercury in contact with a common electrode insures proper contact even though the switch may be jarred ou of its normal operating position.

Referring now to Figure 7, I have disclosed the armature 23 as being provided with a plurality of baffle plates 68 and 69, which baffle plates are preferably set into slots formed in the edges 21 of the armature, and are adapted to prevent any splashing of mercury from the lower electrode 1 upwardly past the cut-away portions of the armature into engagement with the annular ring I 6 of mercury, or with the mercury in the pockets 5l. Thus, if the switch be mounted in position where it may be. subject to Vshock or vibration, there will be no splashing of mercury whichmay produce a sputtering contact which is distinctly undesirable. Preferably'the plates 68 and 59 arequadrant shaped plate members, which have their radially dened edges disposed in vertical alignment, so that the mercury must follow a circultous pathif it is to'pass upwardly past the armature. The arcuate edges of the plates are slightly set back with respect to the edges 21 of the armature, in order that no possibility yof binding of the amature or of varcing from the annular mercury ring I 6 to the plates can be eifected.

I have found that the use of these plates does not in any Way impair the operativeness of the switch during normal operation, and, at the same time, provides for positive elimination of a sputtering contact provided by splashing of the mercury. This is oi distinct importance where the switch may be mounted in moving vehicles or the like.

In Figure 8 I have disclosed the switch, indicated generally by the reference numeral 18, supported within a clamping ring 12 which is provided with oppositely extending pivot members :13 engaging in suitable pivot supports formed in a second ring member 14. The ring member 1l 'is provided with projectingv pivot portions 15 .disposed normally with respect to the pivots '18, and engaging in a fixed supporting ring 18 vsecured to fixed supports 11.

This provides for a binnacle" mounting of the switch, in a manner similar to that in which the compass of a ship is mounted, whereby the switch will always be maintained in proper operating position, regardless of inertia of movement of the ring 16 caused by movement of a vehicle or the like in which it is mounted. 'Ihis mounting is especially adapted for supporting the switch in operative position in railroad cars or similar moving vehicles, in which the switch is used for controlling the circuits of air conditioning, heating or Ventilating apparatus within such vehicles. By this two-way pivotal support of the switch 10, any shocks due to sudden starting or stopping of the car will be absorbed by the pivots, and the switch will not be jarred out of its operative position. Further, inertial movement of the mercury l5, caused by the vehicle rounding a curve or the like, will be accommodated by the pivots, whereby the switch will assume an angular position corresponding to the centrifugal force irnparted to the switch. 'Ihis will provide for maintaining the level of mercury I5 substantially constant regardless of the physical movement of the switch, whereby its operating characteristics and its adaptability to provide for positive performance at the same point during consecutive operations can be maintained.

Referring now in detail to Figures 9 and l0, I have provided, in this embodiment of the invention, a switch structure in which the actuating coil is adapted to selectively control two circuits. In this embodiment of the invention, the lower electrode shell is indicated at 80, and is provided with a terminal lead 82 secured thereto. 'Ihe she1l 80 is adapted to contain a suitable body of mercury 83, and is secured, at its upper edge, to a ceramic member 84. A pair of inwardly extending ring portions 85 and 86 of similar form, having the annular beveled surfaces 81 and 88, defining annular spaces in which mercury 90 is disposed, are disposed within the member 84, the anges 85 and 86 being provided with annular central openings through which a movable armature 92 is adapted to extend. I

.The armature 92, as shown in Figure 10, is formed of an insulating material, such as a ceramic or the like, and is provided with end caps 93. The ceramic shell 92 is iilled with iron shot, lings or the like, indicated generally at 94, whereby it is capable of magnetic attraction by a coil, such as the coil 30 shown in Figure 1.

.Intermediate the ange members 85 and 86 is disposed a metal contact ring 95, which is inconrtact with the annular ring of mercury 90 formed by the flanged and beveled portion 81l of the ring 85. Suitable gaskets may be interposed between the contact member and the ceramic ring portions.

'I'he contact ring 95 is connected, as shown at 86, to a suitable terminal conductor 91 leading to-one circuit controlled by the switch. On initial actuation of the plunger by means of the coil 80, and with a predetermined potential imposed upon the coil 80, the armature 92 is moved downwardly a distance just suilicient to provide for passage of mercury from the main body of mercury 83 up through the central opening in the rflange 85 and over the edge 81 into contact with the annular ring of mercury 9D which, in turn, is in contact with :the metal contacting ring 95. This establishes a circuit between the conductor 82 and the conductor 91.

Upon the imposition of an additional potential upon the coil 80, the armature 92 is moved downwardly still further into the mercury reservoir 83, and forces mercury upwardly through the annular opening in the flange 81 and over 'the annular edge 88 of the ceramic into contactv with the mercury 88 lying between the edge 88 and the inner surface of a cup-shaped electrode 98, which is provided with a terminal conductor 99 suitably secured thereto. This establishes an operating circuit between conductor 82 and the conductor 99. The shell 98 is similar to the shell 6. and is 'I5 provided with a ller plug 99, corresponding to the ller plug |9 of Figure 1.

Preferably, the interior of the switch above the mercury is filled with a suitable liquid as indicated Vat |00, there being a suitable expansion space |02 provided for accommodating expansion of the liquid due to heat caused by contact be tween the bodies of mercury 90 and the mercury from the reservoir 83 passing upwardly past the plunger or armature 92. Thus, by predetermined potential impulses upon the coil 32|, either the circuit between the contact terminal 82 and the conductor 91, or the circuit between the conductor 82 and the conductor 99, can be established. It is apparent that these circuits are established in series, and that the circuit between conductors 82 and 91 will remain established when the plunger 92 is moved downwardly to establish the circuit between conductors 82 and 99. In the same manner, release of the additional potential upon the coil 30 will result only in movement of the plunger upwardly a suicient distance to allow breaking of the circuit between conductors 82 and 99, and will maintain the cir-` cuit between conductors 82 and 91 until the coil 30 is deenergized. Any number of such circuits may be provided ina similar manner. This cir-A cuit is of particular importance in connection'- with control circuits wherein the two control circuits are connected so that they can be operated in the manner described.

In Figure l1 I have disclosed what I term a dual purpose switch, that is, a single switch which is capable of operating two independent circuits upon the actuation of one of two independent actuating means.

In this embodiment of the invention, an actuating coil is shown at |05, and surrounds a lower cup-shaped electrode |06 which is provided, at its upper end, with an outwardly extending iiange portion |01. The flange portion |01 of the electrode |06 is provided, upon opposite surfaces thereof, with gasket means |08, whereby the flange |01 may be gripped in a suitable clamping member |09 which engages over the outer annular surface of a ceramic member ||0, which ceramic member has an internal recess formed therein, as indicated at ||2, and is provided with a centrally extending cylindrical portion ||3 recessed as indicated at H4.

Mounted in the recess |4 of the ceramic member is a sleeve member H5, which forms a conducting electrode to which is connected the terminal conductor ||6. A suitable conductor |1 is connected to the cup-shaped electrode |08.

A second energizing coil ||8 is provided at, and is supported by, the upper end of the sleeve member ||5. The coil ||8 is adapted to have an iron plunger member ||9 supported for axial movement therein, in accordance with energization and deenergization of the coil HB. The lower end of the plunger ||9 is of ceramic material, as indicated at |20, and is adapted to extend through a suitably reduced portion |22 of 4the ceramic member 0 formed at the lower end of the recess H4. Mounted between the lower end of the boss portion ||3 of the ceramic ||0 and the cup-shaped member |00 is a cup-shaped intermediate electrode member indicated at |23, which is adapted to have axial movement with respect to the boss portion ||3 of the ceramic ||0.

The supporting member |09 is provided with a terminal conductor |24 suitably secured thereto, and which is suitably insulated from the sleeve member H5 by means of the insulating gaskets |25. The ceramic member ||0, as illustrated in this embodiment of the invention, is provided with pockets |26 formed in the inner annular surface thereof, and extending through the ceramic ||0 into contact with the inner surface of the member |09. These pockets are adapted to be filled with mercury $21, in a manner similar to that described in connection with the pockets S4 lled with mercury E5 in Figure 6. Further, the extension ||3 of the ceramic is provided, at the lower end of the recess portion ||4 thereof, with an annularly extending recessed portion |28, which is adapted to receive an annular ring ci mercury |29 corresponding to the annular ring of mercury i6 of Figure 1, which is in contact with the inner surface of the sleeve memeber l5.

In operation of this switch, energization of the coil ||8 results in downward movement ofv the plunger member ||9. The ceramic end portion |20 thereof is adapted to be moved downwardly in a body of mercury |30 carried within the cup-shaped electrode |23, which body of mercury moves up through the annular pasageway |22 into contact with the annular ring of mercury |29, and thus contact is effected between theelectrode |06, through the mercury |32 disposed therebetween upon which the electrode 23 ,has floating support, and through the mercury |30 and mercury |29 to the sleeve member ||5, to' which is connected the terminal conductor |l'6. Thus, upon energization of coil ||8, a circuit is closedbetween conductors ||6 and ||1.

Uponv energization of the coil |95, the cupshaped electrode |23 is forced downwardly and outwardly with respect to the lower end of the boss portion I3 of the ceramic, and displaces the mercury |32 in the cup-shaped electrode |05, this mercury passing upwardly over the flanged end |01 of the cup-shaped electrode |06, and into the pockets |26, where it effects contact with the mercury |21 which is in engagement with the member |09. This closes a circuit between the conductors ||1 and |24. It is thus apparent, from this description of the operation of this switch, that independent energization of either the coils |05 or I8 will result in independent control of the circuits between conductors ||1 and |24, and conductors ||1 and H6, respectively. The switch of this embodiment of the invention differs from the switch shown in Figures 9 and 10, in that each of the circuits may be controlled independently of the other circuit, and thus the switch serves the purpose of controlling either one of two operating circuits in accordance with the actuation of either of two actuating means. Energization of coils |05 and ||8, for example, may be responsive -to temperature or humidity conditions, and the circuit controlled by conductors ||1 and IIE, and ||1 and |20, respectively, can be circuits controlling the operation of suitable means for increasing or decreasing humidity and/or temperature conditions. Thus this switch is especially applicable for air conditioning purposes, although it is to be understood that its use is in nowise limited to this particular field.

The switch is preferably provided with a liquid ll, as indicated at |33, in the recess portion ||2 of the ceramic I0, and also a liquid iill |34 within the sleeve member ||5 above the mercury |29. Suitable expansion spaces are provided in both of these annular spaces in order to accommodate expansion of the liquid due to heat generated by controlled by the conductors H6, H1, and I 24.

The proportioning of the electrodes |23, |06, and the ceramic plunger |20 are such that the ceramic plunger can maintain control of the circuit between the body of mercury |30 and the mercury |29 even during movement of the electrode |23. This can be accomplished by having the coil H8 of such potential that, upon downward movement of the electrode |23, the plunger |20 is free to move downwardly an additional amount, whereby contact between the mercury |30 and the mercury |29 will be maintained even during actuation of the electrode |23 by the coil Preferably, the electrode |23 is provided, at its upper end, with slotted portions whereby the levels of the bodies of mercury |30 and |32 can. be controlled so that the proper proportion oi' mercury will be carried at all times within the electrodes |06 and |23.

It is thus apparent that I have provided a switch capable of carrying relatively heavy currents, and which is entirely enclosed and has no exposed moving parts, nor any inleads entering into the interior of the switch housing. In addition, the switch is so constructed as to provide for rapid dissipation of heat therefrom, 'whereby rapidity of action and positiveness of operation, as well as carrying relatively heavy currents, is produced.

In addition, I provide for a mercury to mercury co-ntact between metallic electrodes, which contact is accelerated upon making, and is rapidly broken, by means of a. sharp defining insulating surface over which the contact is made and broken.

I do not intend to be limited to the exact details of the switch structure herein disclosed and described, but only insofar as dened by the scope and spirit of the appended claims.

I claim:

l. In a switch of the class described, a switch housing comprising a pair of hollow metal electrodes secured to an intermediate ceramic spacing member, a body of mercury in one of said electrodes, means dening an annular groove -between said ring and the other of said electrodes vand having an inner dening edge formed at anY acute angle, and magnetically responsive means within said housing for displacing a portion of said mercury over said acute angled edge into contact with the other electrode.

2. In combination, a switch housing comprising a pair of hollow metal electrodes secured to an intermediate ceramic spacing member, an annular series of pockets retaining mercury held in common contact with one of said electrodes by said spacing member, an acute angled spillover edge on said spacing member, a body of mercury in the otherl electrode, and means within said housing for displacing said body of mercury over said edge to secure mercury to mercury contact between said electrodes.

3. In combination, in a switch of the class described, a first electrode having a cylindrical sleeve portion, a second cup-shaped electrode, ceramic spacing means between said electrodes, said spacing means having an inwardly extending annular ange having an axial projecting portion terminating in an acutely angled edge and forming with said sleeve portion an annular series o-f individual pockets containing mercury in commo-n contact with said first electrode, a body of mercury in said second electrode, and

2,103,929- the mercury to mercury closing of the circuits reciprocatory plunger means movable into said body of mercury to displace a portion of said mercury over said edge into contacting engagement with said pockets of mercury.

4. A switch comprising a pair of cup-shaped metallic electrodes disposed with their open ends facing each other, a retaining member having threaded recesses for receiving said ends to form a sealed switch housing, said member having an inwardly extending portion defining an annular Passage between said electrodes, a body of mercury filling one of said electrodes and extending into said passage, a. reciprocatory plunger in said passage for forcing a portion of said mercury from said one electrode through said passage into said other electrode, and means at one end of said plunger adapted to engage said inwardly extending portion to limit movement of said plunger in one direction.

5. In combination, a pair of metallic cupshaped electrodes, an insulating spacing member for receiving the adjacent ends of said electrodes to form a switch housing, said member having an inwardly extending annular portion deiining a. passageway between said electrodes, said member having an annular groove formed between said annular portion and the interior surface of one end of one of said electrodes, a plunger reciprocatory in said passageway, a body of mercury in the other of said 'electrodes and extending up into said passageway, an annular ring of mercury in said groove, means for drawing said plunger down into said mercury to force said body of mercury upwardly through said passageway and into contact with said annular ring of mercury, and radially extending means on said plunger engaging the annular portion of said spacing member for guiding saidplunger axiallytherethrough, said means terminating in outwardly extending abutment members at one end of said plunger for limiting axial movement of said plunger in said passageway.

6. A switch of the class described comprising two cup-shaped metallic electrodes, a ceramic spacer therebetween defining a passageway between said electrodes', a plunger having radially projecting ribs guiding it for reciprocatory movement in said passageway, said spacer having an annular groovey formed therein between one end of one of said electrodes and said passageway, mercury in said groove, and a body of mercury in said other electrode displaced upwardly between the ribs of said plunger through said passageway upon movement of said plunger and adapted to make contact over said spacer with said annular ring of mercury.

7. An actuating member for a switch of the class described comprising a magnetically responsive plunger of generally cruciform section, radially extending rib portions on said plunger having shoulder portions for limiting movement of said plunger in one direction within said switch, and baiiie means projecting normally from the axis of said plunger between said rib portions.

8. An actuating member for a switch of the class described comprising a hollow ceramic member having a laterally serrated surface, means for closing the ends of said member, magnetically responsive material within said meniber, and annular flanges at opposite ends of said member for limiting axial movement of said member within said switch.

9. The combination with a switchv comprising a pair oi cup-shaped metallic electrodes secured to an intermediate ceramic spacing member having an inwardly extending annular flange portion, of actuating means reciprocatory in said flange portion of said spacing member and comprising a' plunger member having a serrated lateral surface for guiding said plunger member, magnetically responsive material in said plunger member, and laterally projecting shoulder means for limiting reciproca-tory movement of said plunger member with respect to said flange portion of said spacing member.

l0. In combination, in a switch including an electrode having a cylindrical sleeve portion, a ceramic supporting member having sealed engagement with the end of said electrode, an inner annular flange portion on said supporting member having a beveled surface extending upwardly and outwardly toward said sleeve portion, a plurality of pockets formed in said surface, and mercury disposed in said pockets and in contact with the inner surface of said electrode;

11. In combination, a switch comprising two metallic cup-shaped electrodes, a ceramic spacer therebetween having an inwardly projecting annular flange portionv of generally T-shaped section, the ends of said section having beveledA edges forming, with the interior surfaces of the ends of said electrodes, annular grooves, a plunger reciprocatory within said annular ilange, a ring of mercury in the upper one of said grooves, and a body of mercury in the lower electrode adapted to be displaced by said plunger into engagement with said ring of mercury for completing a circuit between said electrodes.

12. In combination, a yswitch comprising two metallic cup-shaped electrodes, a ceramic sleeve member between said electrodes, a pair of spaced inwardly extending annular flanges between said electrodes, a Contact ring between said flanges, a reciprocatory plunger movable axially with re spect to said flanges, a body of mercury in one of said electrodes, and annular rings of mercury between one of said flanges and said ring and between the other of said flanges and said other electrode, respectively, said rings of mercury being successively engaged by said body of mercury upon downward movement of said plunger.

13. In combination, a switch comprising a pair of metallic cup-shaped electrodes with a ceramic spacer therebetween defining an annular passage between said electrodes, a reciprocatory plunger in said passage, a clamp surrounding said spacer, and having diametrioally opposed extending pivots, a second ring having bearings for said pivots and having a pair of opposed outwardly extending pivots, a xed ring having bearings for said pivots, and means for holding said fixed ring in a horizontal plane.

14. Actuating means for a switch of the class described comprising a magnetically responsive plunger, said plunger having radially spaced axially extending bearing portions guiding said plunger for reciprocatory movement, and means formed integral with said plungerl for limiting movement thereof in one direction within said switch.

15. In combination, a switch housing, a pair of separately energized actuating coils carried thereby, magnetically responsive plungers energized by said coils, a ceramic spacing member, a plurality of electrodes carried thereby, and a plurality of separated bodies of mercury in contact with said electrodes and said plungers, said vplungers being selectively energized by said actuating coils to establish contact between predecorresponding circuits between said electrodes.

16. A switch of the class described comprising a pair of cup-shaped electrodes, a ceramic spacz tallic electrodes, a ceramic spacer member having intermediate its ends an inwardly extending annular flange provided with an axially projecting beveled edge, said electrodes being threaded into sealing engagement with said spacer member on opposite sides of said flange, an annular ring of mercury confined between the inner end ofl one of said electrodes and said beveled edge, a

plunger member having means guiding it for reciprocatory movement between said electrodes within said annular flange, and a body of mercury in said lower electrode adapted to be displaced by said plunger upwardly past said flange and over said edge into contact with said ring of mercury.

18. In combination, a ceramic spacer, an annular flange formed internally of said spacer, two electrodes on opposite sides of said flange, an an'- nular ring of mercury between one of said electrodes and the inner edge of said flange, a body of mercury in the other electrode, a yplunger reciprooatory within said flange and having radial ribs engaging said flange for guiding reciprocatory movement of said plunger, and out back portions on said ribs adjacent said annular ring of mercury to increase the distance between said ring of mercury and said plunger for preventing arcing therebetween.

19. A plunger adapted to have reciprocatory movement for displacing a body of mercury upwardly therepast into engagement with an annular ring of mercury retained in an annular insulating groove, said plunger comprising a body portion having radially extending guide ribs, outwardly extending projections at one end of said ribs limiting axial movement of said plunger in one direction, and recessed portions in said ribs adjacent said annular ring of mercury to prevent arcing therebetween.

20. A reversible magnetically actuated switch comprising a pair of cup-shaped electrodes, a ceramic spacer receiving the adjacent ends of said electrodes and having an inwardly extending annular flange therebetween defining a passageway between said electrodes, axially extending beveled edges projecting from the inner cylindrical surface of said flange and defining with the adjacent inner end of each of said electrodes an annular groove, a body of mercury in one of said electrodes, a ring of mercury in the annular groove formed at the end of the other electrode, and a reciprocatory plunger for displacing Inercury from said body of mercury into contact with said ring of mercury.

21. A reversible magnetically actuated switch comprising a pair of cup-shaped electrodes, a ceramic spacer receiving the adjacent ends of said electrodes and having an inwardly extending annular ange therebetween defining a pastermined bodies of mercury for completing the" sagewaybetween said electrodes, axially extending 75 beveled edges projecting from the inner cylindrical surface of said fiange and defining with the adjacent inner end of each of said electrodes an annular groove,l a body of mercury in one of said electrodes, a ring of mercury in the annular groove formed at the end of the other electrode, and a reciprocatory plunger for displacing mercury from said body of mercury into contact with said ring of mercury, said plunger having normally projecting portions at its opposite ends for limiting its axial movement in said passageway.

22. A reversible magnetically actuated switch comprising a pair of cup-shaped electrodes, a ceramic spacer receiving the adjacent ends of said electrodes and having an inwardly extending annular flange therebetween defining a passageway between said electrodes, axially extending beveled edges projecting from the inner cylindrical surface of said flange and defining with the adjacent inner end of each of said electrodes an annular groove, a body of mercury in one of said electrodes, a ring of mercury in the annular groove formed at the end of the other electrode, and a reciprocatory plunger for displacing mercury from said body of mercury into contact with said ring of mercury, said plunger having recessed portions disposed adjacent said grooves upon said displacement for preventing arcing between said ring of mercury and said plunger.

23. A switch of the class described comprising a pair of cup-shaped electrodes, the adjacent edges of said electrodes opening toward each other, a ceramicspacer, said electrodes being clamped in insulated relation to said spacer, said spacer having an inwardly extending fiange portion having an axially projecting acutely angled spillover edge spaced from the interior surface of one of said electrodes and defining therewith a mercury retaining recess, a body of mercury therein contacting said interior surface of one of said electrodes, a body of mercury in the other of said electrodes, and a magnetically actuated plunger for displacing a portion of said second body of mercury upwardly past said flange and over said edge into contact with said first body of mercury.

24. A magnetically operated mercury switch comprising a switch housing defined by a pair of cup-shaped metallic electrodes with insulated spacing means between the adjacent open ends thereof, said spacing means including means defining with the inner surface adjacent one end of one of said electrodes a mercury retaining recess, a body of mercury in said recess, a second body of mercury in said other electrode, and a magnetically controlled plunger for displacing a portion of said second body of mercury into ccntact with said first body of mercury.

25.1n combination, a switch envelope comprising two cup-shaped metallic electrodes, a ceramic spacer holding the adjacent open ends of said electrodes in insulated relationship and having means defining with the inside surface of one of said electrodes an annular mercuryn retaining recess, a body of mercury in said recess and a second body of mercury in the other of said electrodes, said second body of mercury being displaceable into contact with said first body of mercury, an alkaline liquid fill in said envelope in contact with said mercury and said electrodes;

and a binnacle mounting for supporting said envelope in operating position.

26. In combination, a switch envelope comprising a pair of vertically spaced cup-shaped electrodes, a ceramic spacer between the adjacent open ends of said electrodes, said electrodes being clamped to said spacer, means on said spacer defining with the interior surface of the upper electrode a recess, a body of mercury in said recess, a second body of mercury in the lower electrode, a plunger for displacing a portion of said second body of mercury into contact with the mercury in said recess, and a binnacle mounting for holding said envelope in vertical position.

27. A spacing member for a mercury switch of the class described comprising an annular ceramic having a radially inwardly extending ange intermediate its ends, and an axially directed lip on the inner periphery of said fiange dening an axially opening annular recess with the inner annular wall of said ceramic adjacent said radial inwardly extending flange.

28. A spacing member for a magnetically operated plunger type mercury switch having electrodes disposed in insulated spaced relation, including an annular internal flange projecting radially inwardly between said electrodes and provided with a series of circumferentially spaced pockets having one wall thereof defined by the internal surface of one of said electrodes and adapted to contain individual bodies of mercury in common contact with said one electrode.

29. An insulating spacing member for a switch of the class described comprising oppositely extending cylindrical fiange portions adapted to receive electrodes in spaced relation, and an internal flange between adjacent ends of said electrodes and defining with one of said electrodes an annular series of mercury-retaining pockets.

30. A switch comprising a pair of cup-shaped electrodes disposed with their adjacent open ends in insulated spaced relationship, an insulating radial fiange between said electrodes, said flange defining with one of said electrodes a series of mercury-retaining pockets.

3l. In combination, a cup-shaped electrode, a ceramic insert in said electrode, a second electrode disposed in abutting engagement with said insert, a body of mercury retained by Said insert in contact with one of said electrodes, a second body of mercury carried by the other electrode, means for supporting said second electrode in sealed and insulated position with respect to said first electrode including sealing gasket means holding said second electrode in position with respect to said insert, means comprising an inwardly crimped edge on said first electrode compressing said gasket means in supporting position, and a reciprocable magnetically controlled plunger for effecting displacement of one of said bodies of mercury into Contact with the other of said bodies of mercury.

32. In combination, a cup-shaped electrode, a ceramic insert in said electrode, a second electrode disposed in abutting engagement with said insert, a body of mercury retained by said insert in contact with one of said electrodes, a second body of mercury carried by the other electrode. said insert forming an insulating passageway for fiow of mercury therethrough to effect mercury- *to-mercury contact between said electrodes, means for supporting said second electrode in sealed and insulated position with respect to said first electrode including sealing gasket means holding said second electrode in position with respect to said insert, means comprising an inwardly crimped edge on said first electrode compressing said gasket means in supporting position, and a reciprocable magnetically controlled plunger for eiecting displacement of one of said bodies of mercury into contact with the other of said bodies of mercury.

33. In combination, a switch envelope comprising a pair of cup-shaped metallic electrodes, an annular spacing ring of insulating material therebetween, an insulating flange extending radially inwardly from said ring between said electrodes and having a normally extending inner edge dening, with the inside surface of one of said electrodes, an annular groove, a body of mercury in said groove, a body of mercury in said other electrode displaceable into contact with said first body of mercury, and means providing a binnacle mounting for supporting said envelope in operative position.

34. In combination, a magnetically controlled switch including a pair of cup-shaped electrodes spaced apart by an insulating ring having annular flange means for retaining an annular ring of mercury in Contact with one of said electrodes and spaced from the other electrode, a body of mercury in the other electrode movable through said ring into contact with said annular ring of mercury, and means providing a binnacle mounting support for said switch.

PAUL S. BEAR. 

